CN111516324B

CN111516324B - Odorless TPU film for diaper and preparation method thereof

Info

Publication number: CN111516324B
Application number: CN202010315593.6A
Authority: CN
Inventors: 王一良; 何建雄; 杨博
Original assignee: Dongguan Xionglin New Materials Technology Co Ltd
Current assignee: Dongguan Xionglin New Materials Technology Co Ltd
Priority date: 2020-04-21
Filing date: 2020-04-21
Publication date: 2022-07-12
Anticipated expiration: 2040-04-21
Also published as: WO2021212900A1; CN111516324A

Abstract

The invention relates to an odorless TPU film for a diaper and a preparation method thereof. The odorless TPU film for the baby diapers is creatively formed by sequentially overlapping nanofiber layers with different performances, each layer is a film which is formed by interweaving nanofibers and has a micro network structure, and the micro network structure can obviously improve the air permeability of the film and is softer; the network-shaped microstructure formed by the nano-fibers is not beneficial to the adhesion of bacterial biofilms and has excellent antibacterial performance; and the network-shaped microstructure has good stability.

Description

Odorless TPU film for diaper and preparation method thereof

Technical Field

The invention belongs to the technical field of synthetic materials, particularly relates to a TPU film and a preparation method thereof, and particularly relates to an odorless TPU film for a diaper and a preparation method thereof.

Background

The diaper is a daily use article for babies, is a general name of paper diapers, paper diapers and pull-ups, is commonly called as the diaper due to strong water absorption, wherein the super absorbent resin is a perfect material for manufacturing the diaper for babies, and has the outstanding characteristic of large water absorption and water storage capacity. Besides strong water absorption capacity, the baby diaper is a baby product, so that the skin of a baby is delicate, the material is required to have excellent air permeability and softness, and the diaper also has excellent antibacterial capacity at best, so that the comfort and the safety are ensured.

Polyurethane is a general name of macromolecular compounds containing repeated urethane groups on main chains, has excellent characteristics of wear resistance, oil resistance, tearing resistance, chemical corrosion resistance and the like, and is widely applied to various fields. However, there are few reports on how to apply TPU materials to the field of diapers, which also limits the wider range of applications for TPU.

CN110318161A discloses a substrate material for a diaper having a grammage in the range of 15-25gsm, an air permeability 3640-6200L/m²S, the water vapor transmission rate is 6720-18560g/cm²24h, oxygen index 29.2-29.4%, water repellency 212-₂O, the shrinkage rate is 0.88-0.91%; the preparation method of the substrate material for the diaper comprises the following steps: preparing master batch, premixing, preparing a basic melt, preparing superfine fibers and carrying out hot rolling treatment; the base material has good flexibility and comfortable hand feeling, and can be widely applied to diapers.

CN108624049A discloses a diaper moisture-retaining antibacterial material and a preparation method thereof, wherein the diaper moisture-retaining antibacterial material comprises the following raw materials: polyether sulfone resin, corn starch, polylactic acid, chitosan, alpha-L-guluronic acid, beta-D-mannuronic acid, gelatin, lignin, artemisia pine, sodium hydroxide, cholic acid, polyasparagine, common andrographis herb, sagebrush root, weeping forsythia capsule, common anemarrhena rhizome, giant knotweed rhizome, silk fibroin, acrylic acid, sodium alginate gel, hydroxyethyl acrylate, glycerol, polyacrylamide, potassium persulfate, sodium sulfite, N-methylene-bisacrylamide, a modified antibacterial auxiliary agent and a water locking reinforcing material.

CN107802879A discloses a water-absorbing polymer material for a diaper and a preparation method thereof, wherein the water-absorbing polymer material comprises the following components in parts by weight: 10-30 parts of common andrographis herb, 5-15 parts of sagebrush root, 30-50 parts of weeping forsythia capsule, 5-20 parts of common anemarrhena rhizome, 15-25 parts of giant knotweed rhizome, 10-25 parts of silk fibroin, 40-50 parts of acrylic acid, 4-8 parts of sodium alginate gel, 25-40 parts of sodium hydroxide, 2-15 parts of hydroxyethyl acrylate, 5-20 parts of glycerol, 5-12 parts of polyacrylamide, 0.5-5 parts of initiator and 0.01-0.05 part of N, N-methylene bisacrylamide. The diaper prepared from the water-absorbing high polymer material has the advantages of higher urine absorption capacity, higher absorption rate and lasting antibacterial and bacteriostatic functions, effectively protects infants from bacterial infection, and provides lasting protection for infants.

The prior art materials for baby diapers are relatively single in function, so that it is very meaningful to develop a material for baby diapers which is breathable, soft, antibacterial and strong in water absorption capacity.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a TPU film and a preparation method thereof, and particularly provides an odorless TPU film for diaper and a preparation method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the invention provides an odorless TPU film for a diaper, which comprises a TPU nanofiber surface layer, a TPU nanofiber middle layer and a TPU nanofiber bottom layer which are sequentially stacked.

The odorless TPU film for the baby diapers is creatively formed by sequentially overlapping a TPU nanofiber surface layer, a TPU nanofiber middle layer and a TPU nanofiber bottom layer, wherein each layer is a film which is formed by interweaving nanofibers and has a microscopic network structure, and the microscopic network structure can obviously improve the air permeability of the film and is softer; the network-shaped microstructure formed by the nano-fibers is not beneficial to the adhesion of bacterial biofilms and has excellent antibacterial performance; and the network-shaped microstructure has good stability.

In the invention, the TPU nanofiber surface layer comprises polyurethane nanofibers, polydimethylsiloxane nanofibers, an antibacterial agent, talcum powder and erucamide, and the antibacterial agent, the talcum powder and the erucamide are dispersed in the polyurethane nanofibers.

The TPU nanofiber surface layer is a film which is formed by interweaving polyurethane nanofibers and polydimethylsiloxane nanofibers and has a micro-network-like structure, and the micro-network-like structure can obviously improve the air permeability of the film and is softer; polyurethane is a material with better flexibility, and the flexibility of the film can be further increased by matching the polyurethane with polydimethylsiloxane. In addition, the network-shaped microstructure formed by the polyurethane nano-fibers is not beneficial to the adhesion of bacterial biofilms and has excellent antibacterial performance, so that the antibacterial agent dispersed in the antibacterial agent can effectively exert the antibacterial performance. And the network-shaped microstructure has good stability. The addition of the talcum powder and the erucamide ensures that the product has better smoothness and good anti-adhesion performance; the friction force and adhesive force between the polymer and equipment and between the polymer and the polymer can be effectively reduced, and the processing speed and the product quality are greatly improved.

Preferably, the TPU nanofiber surface layer comprises, by weight, 20-40 parts of polyurethane nanofibers, 30-40 parts of polydimethylsiloxane nanofibers, 1-3 parts of an antibacterial agent, 1-3 parts of talcum powder and 1-3 parts of erucamide.

The polyurethane nanofiber may be 20 parts, 22 parts, 25 parts, 26 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, or the like by weight.

The polydimethylsiloxane nano-fiber can be 30 parts, 32 parts, 34 parts, 35 parts, 36 parts, 38 parts, 39 parts or 40 parts by weight.

The antibacterial agent can be 1 part, 1.5 parts, 2 parts, 2.5 parts or 3 parts by weight.

The talcum powder can be 1 part, 1.5 parts, 2 parts, 2.5 parts or 3 parts by weight.

The erucamide can be 1 part, 1.5 parts, 2 parts, 2.5 parts or 3 parts by weight.

In the invention, the TPU nanofiber middle layer comprises polyurethane nanofibers and sodium polyacrylate nanofibers.

The TPU nanofiber middle layer is a film with a micro-network-shaped structure formed by interweaving polyurethane nanofibers and sodium polyacrylate nanofibers, the film has the air permeability and the stability, and the sodium polyacrylate nanofibers also have strong water absorption and storage capacities and are particularly suitable for preparing the diaper.

Preferably, the TPU nanofiber middle layer comprises 20-40 parts of polyurethane nanofibers and 30-50 parts of sodium polyacrylate nanofibers in parts by weight.

The polyurethane nanofiber may be in an amount of 20 parts, 22 parts, 25 parts, 26 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, or the like by weight.

The weight parts of the sodium polyacrylate nanofiber are 30 parts, 32 parts, 35 parts, 36 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 parts or 50 parts and the like.

In the invention, the TPU nanofiber substrate comprises polyurethane nanofibers, polydimethylsiloxane nanofibers and an antibacterial agent, and the antibacterial agent is dispersed in the polyurethane nanofibers.

Preferably, the TPU nanofiber substrate comprises, by weight, 20-40 parts of polyurethane nanofibers, 10-20 parts of polydimethylsiloxane nanofibers and 5-10 parts of an antibacterial agent.

The polydimethylsiloxane nano-fiber can be 10 parts, 12 parts, 14 parts, 15 parts, 16 parts, 18 parts, 19 parts or 20 parts by weight.

The antibacterial agent can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts by weight.

Preferably, the preparation raw materials of the polyurethane nanofiber comprise 20-40 parts of diisocyanate, 40-80 parts of polyethylene glycol and 5-20 parts of a chain extender in parts by weight.

The diisocyanate may be present in an amount of 20, 25, 28, 30, 32, 34, 35, 38, or 40 parts by weight.

The polyethylene glycol can be 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts or 80 parts by weight.

The weight portion of the chain extender can be 5, 8, 10, 12, 15, 16, 17, 18 or 20 parts.

Preferably, the diisocyanate comprises any one or a combination of at least two of p-phenylene diisocyanate, methylene diisocyanate or diphenylmethane diisocyanate; combinations of the at least two such as a combination of p-phenylene diisocyanate and methylene diisocyanate, a combination of methylene diisocyanate and diphenylmethane diisocyanate, a combination of p-phenylene diisocyanate and diphenylmethane diisocyanate, and the like. A combination of p-phenylene diisocyanate and methylene diisocyanate is preferred.

Preferably, the chain extender comprises any one of ethylene glycol, ethylene diamine, 1, 3-propanediol, 1, 4-butanediol or hexanediol or a combination of at least two thereof; the combination of at least two of the foregoing, for example, a combination of ethylene glycol and ethylenediamine, a combination of 1, 3-propanediol and 1, 4-butanediol, a combination of 1, 4-butanediol, hexanediol and diethylene glycol, and the like, and any other combination method is not described in detail. A combination of ethylene glycol and ethylene diamine is preferred.

Preferably, the polyethylene glycol has a number average molecular weight of 8000-.

Preferably, the preparation raw material of the polyurethane nanofiber further comprises 5-10 parts of a catalyst and/or 10-20 parts of an antioxidant in parts by weight.

The catalyst can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts by weight.

The antioxidant can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 18 parts or 20 parts by weight.

Preferably, the antibacterial agent comprises any one of chitosan quaternary ammonium salt, chitosan hydrochloride or hydroxypropyl chitosan or a combination of at least two of the chitosan quaternary ammonium salt, the chitosan hydrochloride and the hydroxypropyl chitosan; such as a combination of chitosan quaternary ammonium salt and chitosan hydrochloride, a combination of chitosan hydrochloride and hydroxypropyl chitosan, a combination of chitosan quaternary ammonium salt and hydroxypropyl chitosan, and the like, preferably chitosan quaternary ammonium salt.

The antibacterial agents related to the invention are all natural harmless antibacterial agents, and have no stimulation, no harm and no odor to the skin of the infant.

In another aspect, the present invention provides a method for preparing an odorless TPU film for diaper, the method comprising the steps of:

(1) dissolving components in the TPU nanofiber surface layer, the TPU nanofiber intermediate layer and the TPU nanofiber bottom layer in an organic solvent according to parts by weight respectively to obtain a dissolved solution;

(2) and (2) sequentially carrying out three-layer multi-nozzle electrostatic spinning on the solution obtained in the step (1) to obtain the odorless TPU film for the baby diapers.

The odorless TPU film for the baby diapers is prepared by utilizing an electrostatic spinning technology, is simple and easy to implement, and is suitable for large-scale industrial production.

The preparation method of the polyurethane material comprises the following steps: diisocyanate, polyethylene glycol, a chain extender, a catalyst and an antioxidant are mixed and then react to obtain the polyurethane composite material.

The reaction is carried out under stirring. The stirring rate is 600-800r/min, such as 600r/min, 620r/min, 650r/min, 680r/min, 700r/min, 750r/min or 800 r/min.

The reaction is carried out under vacuum dehydration conditions. The reaction temperature is 130-150 ℃, such as 130 ℃, 132 ℃, 135 ℃, 137 ℃, 140 ℃, 142 ℃, 145 ℃, 148 ℃ or 150 ℃.

The reaction time is 2-8h, such as 2h, 3h, 4h, 5h, 6h, 7h or 8h, and the like.

Preferably, the organic solvent in step (1) comprises any one of N, N-dimethylformamide, acetone or hexafluoroisopropanol or a combination of at least two thereof. Combinations of the at least two, for example, a combination of N, N-dimethylformamide and acetone, a combination of acetone and hexafluoroisopropanol, a combination of N, N-dimethylformamide and hexafluoroisopropanol, and the like.

Preferably, the inner diameter of the nozzle for electrostatic spinning in step (2) is 0.4-0.6mm, such as 0.4mm, 0.5mm or 0.6 mm.

Preferably, the voltage of the electrostatic spinning in the step (2) is 12-16kV, such as 12kV, 13kV, 14kV, 15kV or 16 kV.

Preferably, the distance between the tip and the collector of said electrospinning of step (2) is 12-16cm, such as 12cm, 13cm, 14cm, 15cm or 16cm, etc.

Preferably, the temperature at which the electrostatic spinning is carried out is 20 to 30 ℃, for example, 20 ℃, 22 ℃, 24 ℃, 25 ℃, 26 ℃, 28 ℃, 29 ℃, or 30 ℃.

Preferably, the feed rate for the electrospinning in step (2) is 0.5-1.0mL/L, such as 0.5mL/L, 0.6mL/L, 0.7mL/L, 0.8mL/L, 0.9mL/L, or 1.0mL/L, etc.

The above definition of the series of parameters in electrospinning enables the final product to obtain the above beneficial effects.

Preferably, the step (2) of obtaining the odorless TPU film for baby diapers further comprises a post-treatment operation, wherein the post-treatment operation comprises the following steps: the odorless TPU film for the diaper is dried under vacuum at 20-30 ℃ (e.g. 20 ℃, 22 ℃, 25 ℃, 27 ℃ or 30 ℃ and the like) for 24-72h (e.g. 24h, 30h, 40h, 50h, 60h or 72h and the like).

As a preferred technical scheme of the invention, the preparation method specifically comprises the following steps:

(1) mixing and dissolving polyurethane, an antibacterial agent, talcum powder and erucamide in a solvent according to parts by weight, and dissolving polydimethylsiloxane in the solvent according to parts by weight to obtain two solutions of a TPU nanofiber surface layer;

(2) respectively dissolving polyurethane and sodium polyacrylate in a solvent according to parts by weight to obtain two solutions of the TPU nanofiber intermediate layer;

(3) mixing and dissolving polyurethane and an antibacterial agent in a solvent according to parts by weight, and dissolving polydimethylsiloxane in the solvent according to parts by weight to obtain two solutions of a TPU nanofiber bottom layer;

(4) and sequentially carrying out three-layer multi-nozzle electrostatic spinning on the obtained solution to obtain the odorless TPU film for the baby diapers.

Compared with the prior art, the invention has the following beneficial effects:

the odorless TPU film for the baby diapers is creatively formed by sequentially overlapping three layers, namely a TPU nanofiber surface layer, a TPU nanofiber middle layer and a TPU nanofiber bottom layer, which have different performances, and each layer is a film with a micro-network-shaped structure formed by interweaving nanofibers, so that the air permeability of the film can be remarkably improved and the film is softer; the network-shaped microstructure formed by the nano-fibers is not beneficial to the adhesion of bacterial biofilms and has excellent antibacterial performance; and the network-shaped microstructure has good stability.

The TPU nanofiber surface layer and the TPU nanofiber bottom layer are films with a microscopic network structure formed by interweaving polyurethane nanofibers and polydimethylsiloxane nanofibers, and the antibacterial agent is dispersed in the polyurethane nanofibers; polyurethane is a material with better flexibility, and the flexibility of the film can be further increased by using the polyurethane and polydimethylsiloxane together.

The TPU nanofiber middle layer is a film with a micro-network structure formed by interweaving polyurethane nanofibers and sodium polyacrylate nanofibers, the film has the air permeability and the stability, and the sodium polyacrylate nanofibers also have strong water absorption and storage capacity and are particularly suitable for preparation of urine-proof materials.

Detailed Description

To further illustrate the technical means and effects of the present invention, the following further describes the technical solution of the present invention with reference to the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

The sodium polyacrylate referred to in the following examples was prepared by the following method:

22 parts of acrylic acid, 7 parts of sodium hydroxide, 0.8 part of PVA and 0.05 part of (NH)₄)₂S₂O₈And 0.05 part of (CH)₂CCONH)₂CH₂Stirring in a jacketed reaction tank with a stirrer, performing prepolymerization and polymerization reaction in sequence, and drying to obtain the final product.

The polyurethanes referred to in the following examples were prepared using the following method:

mixing 15 parts of p-phenylene diisocyanate, 15 parts of diphenylmethane diisocyanate, 60 parts of polyethylene glycol (PEG8000), 5 parts of ethylene glycol, 5 parts of ethylenediamine, 5 parts of catalyst (stannous octoate) and 10 parts of antioxidant (CHEMNOX1010) in proportion, reacting, and stirring and reacting at the speed of 1500r/min for 15 hours under the vacuum dehydration condition at 110 ℃ to obtain the polyurethane material.

The polydimethylsiloxane in the following examples had a viscosity (25 ℃ C. cp) of 10000.

Example 1

The invention provides an odorless TPU film for a diaper, which comprises a TPU nanofiber surface layer, a TPU nanofiber middle layer and a TPU nanofiber bottom layer which are sequentially overlapped.

The TPU nanofiber surface layer comprises, by weight, 30 parts of polyurethane nanofibers, 35 parts of polydimethylsiloxane nanofibers, 2 parts of an antibacterial agent, 1 part of talcum powder and 1 part of erucamide.

The TPU nanofiber middle layer comprises 30 parts of polyurethane nanofiber and 40 parts of sodium polyacrylate nanofiber in parts by weight.

The TPU nanofiber bottom layer comprises, by weight, 30 parts of polyurethane nanofibers, 15 parts of polydimethylsiloxane nanofibers and 8 parts of an antibacterial agent.

The preparation method comprises the following steps:

(1) mixing and dissolving polyurethane, an antibacterial agent (chitosan hydrochloride), talcum powder and erucamide in acetone according to parts by weight, and dissolving polydimethylsiloxane in acetone according to parts by weight to obtain two solutions of the TPU nanofiber surface layer;

(2) respectively dissolving polyurethane and sodium polyacrylate in acetone according to parts by weight to obtain two solutions of the TPU nanofiber middle layer;

(3) mixing and dissolving polyurethane and an antibacterial agent (chitosan hydrochloride) in acetone according to parts by weight, and dissolving polydimethylsiloxane in acetone according to parts by weight to obtain two solutions of a TPU nanofiber bottom layer;

(4) sequentially carrying out three-layer electrostatic spinning by using 2-nozzle electrostatic spinning equipment to obtain the odorless TPU film for the baby diapers, and carrying out vacuum drying for 48 hours at the temperature of 25 ℃; the inner diameter of the spray head is 0.4 mm; the voltage is 15 kV; the distance between the needle tip and the collector is 16 cm; the feed rate was 0.5 mL/L.

Example 2

The TPU nanofiber surface layer comprises, by weight, 40 parts of polyurethane nanofibers, 40 parts of polydimethylsiloxane nanofibers, 3 parts of an antibacterial agent, 1 part of talcum powder and 1 part of erucamide.

The TPU nanofiber middle layer comprises 40 parts of polyurethane nanofiber and 50 parts of sodium polyacrylate nanofiber in parts by weight.

The TPU nanofiber bottom layer comprises 40 parts of polyurethane nanofibers, 20 parts of polydimethylsiloxane nanofibers and 10 parts of an antibacterial agent in parts by weight.

The preparation method comprises the following steps:

(1) mixing and dissolving polyurethane, an antibacterial agent (chitosan quaternary ammonium salt), talcum powder and erucamide in parts by weight into N, N-dimethylformamide, and dissolving polydimethylsiloxane in parts by weight into the N, N-dimethylformamide to obtain two solutions of a TPU nanofiber surface layer;

(2) respectively dissolving polyurethane and sodium polyacrylate in N, N-dimethylformamide according to parts by weight to obtain two solutions of a TPU nanofiber middle layer;

(3) mixing and dissolving polyurethane and an antibacterial agent (chitosan quaternary ammonium salt) in N, N-dimethylformamide in parts by weight, and dissolving polydimethylsiloxane in N, N-dimethylformamide in parts by weight to obtain two solutions of a TPU nanofiber bottom layer;

(4) sequentially carrying out three-layer electrostatic spinning by using 2-nozzle electrostatic spinning equipment to obtain the odorless TPU film for the baby diapers, and carrying out vacuum drying for 48 hours at the temperature of 25 ℃; the inner diameter of the spray head is 0.4 mm; the voltage is 15 kV; the distance between the needle tip and the collector electrode is 16 cm; the liquid inlet speed was 0.5 mL/L.

Example 3

The TPU nanofiber surface layer comprises, by weight, 20 parts of polyurethane nanofibers, 30 parts of polydimethylsiloxane nanofibers, 1 part of an antibacterial agent, 1 part of talcum powder and 1 part of erucamide.

The TPU nanofiber middle layer comprises 20 parts of polyurethane nanofiber and 30 parts of sodium polyacrylate nanofiber in parts by weight.

The TPU nanofiber bottom layer comprises 20 parts of polyurethane nanofibers, 10 parts of polydimethylsiloxane nanofibers and 5 parts of an antibacterial agent in parts by weight.

The preparation method comprises the following steps:

(1) mixing and dissolving polyurethane, an antibacterial agent (hydroxypropyl chitosan), talcum powder and erucamide in N, N-dimethylformamide in parts by weight, and dissolving polydimethylsiloxane in N, N-dimethylformamide in parts by weight to obtain two solutions of the TPU nanofiber surface layer;

(2) respectively dissolving polyurethane and sodium polyacrylate in N, N-dimethylformamide in parts by weight to obtain two solutions of the TPU nanofiber middle layer;

(3) mixing and dissolving polyurethane and an antibacterial agent (hydroxypropyl chitosan) in N, N-dimethylformamide in parts by weight, and dissolving polydimethylsiloxane in N, N-dimethylformamide in parts by weight to obtain two solutions of a TPU nanofiber bottom layer;

(4) sequentially carrying out three-layer electrostatic spinning by using 2-nozzle electrostatic spinning equipment to obtain the odorless TPU film for the baby diapers, and carrying out vacuum drying for 48 hours at the temperature of 25 ℃; the inner diameter of the spray head is 0.4 mm; the voltage is 15 kV; the distance between the needle tip and the collector electrode is 16 cm; the feed rate was 0.5 mL/L.

Example 4

The invention provides an odorless TPU film for a diaper, which comprises a TPU nanofiber surface layer, a TPU nanofiber middle layer and a TPU nanofiber bottom layer which are sequentially overlapped. Wherein the polydimethylsiloxane nanofibers are not contained therein.

The TPU nanofiber surface layer comprises 65 parts of polyurethane nanofiber, 2 parts of antibacterial agent (chitosan hydrochloride), 1 part of talcum powder and 1 part of erucamide in parts by weight.

The TPU nanofiber bottom layer comprises 45 parts of polyurethane nanofibers and 8 parts of an antibacterial agent (chitosan hydrochloride) according to parts by weight.

The preparation method of the composite material is different from that of the embodiment 1 only in that the surface layer and the bottom layer are spun by using single-nozzle electrostatic spinning equipment, and the others are consistent.

Example 5

The invention provides an odorless TPU film for a diaper, which comprises a TPU nanofiber surface layer, a TPU nanofiber middle layer and a TPU nanofiber bottom layer which are sequentially overlapped. Which does not contain an antibacterial agent.

The TPU nanofiber surface layer comprises, by weight, 30 parts of polyurethane nanofibers, 35 parts of polydimethylsiloxane nanofibers, 1 part of talcum powder and 1 part of erucamide.

The TPU nanofiber bottom layer comprises 30 parts of polyurethane nanofibers and 15 parts of polydimethylsiloxane nanofibers in parts by weight.

The preparation process was identical to example 1.

Example 6

The invention provides an odorless TPU film for a diaper, which comprises a TPU nanofiber surface layer, a TPU nanofiber middle layer and a TPU nanofiber bottom layer which are sequentially overlapped. Sodium polyacrylate nanofibers are not contained.

The TPU nanofiber surface layer comprises, by weight, 30 parts of polyurethane nanofibers, 35 parts of polydimethylsiloxane nanofibers, 2 parts of an antibacterial agent (chitosan hydrochloride), 1 part of talcum powder and 1 part of erucamide.

The TPU nanofiber middle layer comprises 70 parts of polyurethane nanofiber in parts by weight.

The TPU nanofiber bottom layer comprises 30 parts of polyurethane nanofibers, 15 parts of polydimethylsiloxane nanofibers and 8 parts of an antibacterial agent (chitosan hydrochloride) in parts by weight.

The preparation method is different from that of the embodiment 1 only in that the middle layer is spun by adopting single-nozzle electrostatic spinning equipment, and the others are consistent.

Comparative example 1

This comparative example provides a TPU film including a TPU skin layer, a TPU intermediate layer, and a TPU base layer stacked in this order.

The TPU surface layer comprises, by weight, 40 parts of polyurethane, 40 parts of polydimethylsiloxane, 3 parts of an antibacterial agent (chitosan hydrochloride), 1 part of talcum powder and 1 part of erucamide.

The TPU nanofiber middle layer comprises 40 parts of polyurethane and 50 parts of sodium polyacrylate in parts by weight.

The TPU nanofiber bottom layer comprises, by weight, 40 parts of polyurethane, 20 parts of polydimethylsiloxane and 10 parts of an antibacterial agent (chitosan hydrochloride).

The preparation method comprises the following steps:

(1) mixing polyurethane, polydimethylsiloxane, an antibacterial agent, talcum powder and erucamide according to a ratio to obtain a TPU surface layer mixture; mixing polyurethane and sodium polyacrylate according to a ratio to obtain a TPU intermediate layer mixture; mixing polyurethane, polydimethylsiloxane and an antibacterial agent according to a ratio to obtain a TPU bottom layer mixture;

(2) respectively extruding the three mixtures obtained in the step (1) by using a double-screw extruder, and then laminating to obtain the TPU film;

(3) and (3) drying the TPU film obtained in the step (2) at 25 ℃ for 48 hours in vacuum.

Evaluation test

(1) Water vapor transmission rate test

The TPU films obtained in examples 1 to 6 and comparative example 1 were subjected to a water vapor transmission rate test (test method GB/T1037-.

TABLE 1

From the data results in table 1, it can be seen that: comparing the data of examples 1 to 6 with that of comparative example 1, it can be seen that the odorless TPU film for a diaper according to the present invention has excellent air permeability; as can be seen from the data of examples 1 and 4, the single type of nanofiber layer will have somewhat better air permeability than the multiple type of nanofiber layer; as can be seen from the data of examples 1 and 5, the product containing no antimicrobial in the nanofibers will have somewhat better air permeability than the product containing the antimicrobial; it can be seen from the data of examples 1 and 6 that a single type of nanofiber layer will have a slightly better air permeability than a plurality of types of nanofiber layers.

(2) Evaluation of Sterilization Properties

The TPU films prepared in the above examples 1-6 and comparative example 1 are subjected to antibacterial performance evaluation, and the model bacteria are gram-positive bacteria: staphylococcus aureus, enterococcus faecalis; gram-negative bacteria: escherichia coli. The operation method comprises the following steps: respectively activating and amplifying staphylococcus aureus, enterococcus faecalis, pseudomonas aeruginosa, escherichia coli and monascus, and diluting to 5 × 10⁵Absorbing 200 mu L of bacterial suspension liquid by a sterile pipette respectively, uniformly coating the bacterial suspension liquid on the surface layer of each sample, and culturing for 24h at 37 ℃; then washing off bacteria on the surface of the sample with an equal volume of culture medium, culturing at 37 ℃ for 8h, diluting, plating, and countingColony counts for group samples (data units in the table are CFU/mL, each sample is replicated 3 times in parallel, and averaged). The results are shown in Table 2.

TABLE 2

From the data results of table 2, it can be seen that: comparing the data of examples 1 to 6 with the data of comparative example 1, it can be seen that the odorless TPU film for diaper according to the present invention has excellent bacteriostatic properties; as can be seen from the data of examples 1 and 4, a single type of nanofiber layer will have about the same bacteriostatic activity as a plurality of types of nanofiber layers; as can be seen from the data of examples 1 and 5, the product containing no antimicrobial agent in the nanofibers has significantly reduced bacteriostatic properties compared to the product containing the antimicrobial agent; as can be seen from the data of example 1 and example 6, a single type of nanofiber layer will have about the same bacteriostatic activity as a multiple type nanofiber layer.

(3) Evaluation of extensibility and softness

The TPU films prepared in the above examples 1-6 and comparative example 1 are subjected to extensibility and softness evaluation, and the extensibility is evaluated by the method GB/T24218.3-2010; the softness adopts the method GB/T8942-2002. The test results are shown in table 3.

TABLE 3

From the data results in table 3, it can be seen that: comparing the data of examples 1-6 with that of comparative example 1, it can be seen that the odorless TPU film for diaper of the present invention has excellent elongation and softness; as can be seen from the data of examples 1 and 4, the absence of polydimethylsiloxane fiber significantly worsens the extensibility and softness of the product; as can be seen from the data of example 1 and example 5, the absence of the antibacterial agent rather promotes the extensibility of the product to some extent; it can be seen from the data of examples 1 and 6 that the absence of sodium polyacrylate fibers and the replacement with polyurethane fibers will promote the extensibility of the product to some extent.

(4) Evaluation of Water absorption Properties

The TPU films prepared in the above examples 1 to 6 and comparative example 1 were evaluated for their water absorption properties by the method of GB/T22905-2008. The test results are shown in table 4.

TABLE 4

Sample (I)	Liquid absorption amount g/g	Imbibition rate s
			Example 1	1128	56
Example 2	1093	52
			Example 3	1115	59
Example 4	1017	55
			Example 5	1187	56
Example 6	365	24
			Comparative example 1	952	36

From the data results in table 4, it can be seen that: comparing the data of examples 1 to 6 with that of comparative example 1, it can be seen that the odorless TPU film for a diaper according to the present invention has excellent water absorbing properties; as can be seen from the data of examples 1 and 4, the absence of polydimethylsiloxane fibers does not have an effect on the water absorption properties of the product; as can be seen from the data of example 1 and example 5, the absence of antimicrobial does not have an effect on the water absorption properties of the product; as can be seen from the data of examples 1 and 6, the absence of sodium polyacrylate fibers significantly reduces the water absorption properties of the product.

The applicant states that the present invention is illustrated by the above examples to a non-odor TPU film for baby diapers and a method for preparing the same, but the present invention is not limited to the above examples, i.e., it does not mean that the present invention must be implemented by the above examples. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

Claims

1. The odorless TPU film for the baby diapers is characterized by comprising a TPU nanofiber surface layer, a TPU nanofiber middle layer and a TPU nanofiber bottom layer which are sequentially overlapped;

the TPU nanofiber surface layer comprises, by weight, 20-40 parts of polyurethane nanofibers, 30-40 parts of polydimethylsiloxane nanofibers, 1-3 parts of an antibacterial agent, 1-3 parts of talcum powder and 1-3 parts of erucamide, wherein the antibacterial agent, the talcum powder and the erucamide are dispersed in the polyurethane nanofibers;

the TPU nanofiber middle layer comprises, by weight, 20-40 parts of polyurethane nanofibers and 30-50 parts of sodium polyacrylate nanofibers;

the TPU nanofiber bottom layer comprises 20-40 parts of polyurethane nanofibers, 10-20 parts of polydimethylsiloxane nanofibers and 5-10 parts of antibacterial agents in parts by weight, and the antibacterial agents are dispersed in the polyurethane nanofibers;

the antibacterial agent is chitosan quaternary ammonium salt;

the odorless TPU film for the baby diapers is prepared by a preparation method comprising the following steps of:

(1) dissolving components contained in the TPU nanofiber surface layer, the TPU nanofiber middle layer and the TPU nanofiber bottom layer in an organic solvent according to parts by weight respectively to obtain a dissolved solution;

2. The odorless TPU film as claimed in claim 1, wherein the raw materials for preparing the polyurethane nanofiber comprise, by weight, 20-40 parts of diisocyanate, 40-80 parts of polyethylene glycol and 5-20 parts of chain extender.

3. The odorless TPU film of claim 2 wherein the diisocyanate comprises any one or a combination of at least two of p-phenylene diisocyanate, methylene diisocyanate or diphenylmethane diisocyanate.

4. The odorless TPU film of claim 2 wherein the diisocyanate is a combination of p-phenylene diisocyanate and methylene diisocyanate.

5. The odorless TPU film of claim 2 wherein the chain extender comprises any one of or a combination of at least two of ethylene glycol, ethylene diamine, 1, 3-propanediol, 1, 4-butanediol, or hexanediol.

6. The odorless TPU film of claim 2 wherein the chain extender is a combination of ethylene glycol and ethylene diamine.

7. The odorless TPU film of claim 2 wherein the polyethylene glycol has a number average molecular weight of 8000-10000.

8. The odorless TPU film as claimed in claim 2, wherein the raw materials for preparing the polyurethane nanofiber further comprise 5 to 10 parts by weight of a catalyst and/or 10 to 20 parts by weight of an antioxidant.

9. The method for preparing an odorless TPU film for urine absorption according to any one of claims 1 to 8, wherein the preparation method comprises the steps of:

10. The method of preparing an odorless TPU film for urine absorption according to claim 9 wherein the organic solvent of step (1) comprises any one or a combination of at least two of N, N-dimethylformamide, acetone or hexafluoroisopropanol.

11. The method of preparing an odorless TPU film for a diaper of claim 9 wherein the inner diameter of the nozzle of the electrospinning of step (2) is 0.4 to 0.6 mm.

12. The method for preparing an odorless TPU film for urine absorption according to claim 9 wherein the voltage of the electrospinning in the step (2) is 12 to 16 kV.

13. The method of preparing an odorless TPU film for a diaper according to claim 9 wherein the distance between the tip of the electrospinning needle and the collector in the step (2) is 12 to 16 cm.

14. The method for preparing an odorless TPU film of claim 9 wherein the temperature at which electrospinning is carried out is 20 to 30 ℃.

15. The method of preparing an odorless TPU film of claim 9 wherein the feed rate of the electrospinning of step (2) is 0.5 to 1.0 mL/L.

16. The method for preparing an odorless TPU film for urine absorption according to claim 9, wherein the step (2) of obtaining the odorless TPU film for urine absorption further comprises a post-treatment operation, wherein the post-treatment operation comprises the following steps: and (3) drying the odorless TPU film for the diaper in vacuum at the temperature of 20-30 ℃ for 24-72 h.

17. The method for preparing the odorless TPU film for the baby diapers according to claim 9, wherein the preparation method comprises the following steps:

(2) respectively dissolving polyurethane and sodium polyacrylate in a solvent according to parts by weight to obtain two solutions of a TPU nanofiber middle layer;